Blood pump

ABSTRACT

Blood pump for percutaneous insertion into a heart&#39;s ventricle comprising an electrical motor for driving the blood pump, the electrical motor comprising at least tree motor winding units, wherein each motor winding unit is individually connectable to a power supply via two separate phase supply lines connected to the respective motor winding unit terminals. Motor controller for driving and controlling the electrical motor of the blood pump, wherein the motor controller comprises corresponding phase supply line driving units for each motor winding units of the electrical motor of the blood pump which phase supply line driving units are connected via the corresponding two-phase supply lines with the corresponding motor winding unit. Blood pump system comprising the blood pump and the motor controller. Control method for controlling the power supply to the motor winding units of the blood pump, wherein the method comprises: detecting a fault of one of the motor winding units, and in case of a detected faulty motor winding unit, switching off the corresponding phase supply line driving unit of the faulty motor winding unit and further operating the electrical motor by the remaining motor winding units, or, alternatively, adjusting driving parameters of the faulty motor winding unit and further operating the electrical motor by all motor winding units. Use of at least three independent motor winding units in an electrical motor for driving of a blood pump for percutaneous insertion, which motor winding units are individually connected to corresponding power supply via corresponding two separate phase supply lines connected to respective motor winding unit terminals of one of the at least three motor winding units.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 16/484,423, filed on Aug. 7, 2019, now allowed, which is anational phase entry under 35 U.S.C. § 371 of International ApplicationNo. PCT/EP2018/052797, filed Feb. 5, 2018, published as InternationalPublication No. WO 2018/146045 A1, which claims priority to EuropeanPatent Application No. 17155078.3, filed Feb. 7, 2017, the disclosuresof which are hereby incorporated herein by reference.

FIELD OF THE INVENTION

The present invention concerns the field of ventricular assist devices(VAD) for percutaneous insertion. In particular, the invention relatesto the circuitry configuration of motor winding units in the motor ofthe VAD, such as percutaneous insertable blood pump, for example anintravascular rotary blood pump and the control as well as controldevice of such a VAD.

BACKGROUND OF THE INVENTION

VADs driven by an electrical motor having motor windings are in generalknown. One particular example of a VAD such as a percutaneous insertableblood pump is a catheter-based rotary blood pump arranged to be placedor implanted directly through blood vessels into the heart for severalhours or days for assisting the heart function until recovery.

U.S. Pat. No. 5,911,685 A discloses an exemplary intravascular rotaryblood pump. However, there are other types of VADs comprising electricalmotors as well.

An electrical motor for driving the VAD is one important component ofthe VAD with regard to functionality of the VAD and so for providing therequired assistance to the heart of a patient. Failure of the motor maycause serious problems and even if the VAD can be replaced such areplacement imposes an unnecessary risk.

SUMMARY OF THE INVENTION

It is a first object of the present invention to provide an improvedelectrical drive for VADs by which the risk of a failing electricalmotor can be reduced and in particular a complete drop out of theelectrical motor can be avoided.

Further, it is a second object of the present invention to provide animproved control method and device for an improved electrical motorachieving the first object, for further operating the electrical motorin the event of a failing motor winding.

At least one of the objects is achieved by the features of therespective independent claims. Further embodiments are defined in therespective dependent claims.

The core idea of the present invention is to use an electrical motor fordriving the VAD, in particular a percutaneous insertable blood pump suchas an intravascular rotary blood pump, in which the motor windings arearranged in a circuitry configuration that avoids any circuitryinterconnection between anyone and the respective other motor windings.Preferably, all motor windings are individually operated via separatesupply lines. Advantageously, the electrical motor may still be operatedif there is failure with anyone of the motor windings by placing theaffected motor winding out of operation or operating the affected motorwinding with adjusted parameters. For example, if there is aninterruption in one of the phase supply lines for any one of the motorwindings, the electrical motor can still be operated by means of theremaining motor windings. For example, if there is a short circuitbetween two particular windings, one of the affected windings can beplaced out of operation so that the electrical motor can still beoperated by means of the remaining motor windings. For example, if thereis a short circuit within one particular winding (e.g., a turn-to-turnshort circuit), the affected winding can be placed out of operation oroperated with adjusted parameters so that the electrical motor can stillbe operated by means of the remaining motor windings. For example, ifthere is a fault current from a particular winding to, for example, thepump's casing, the affected winding can be placed out of operation sothat the electrical motor can still be operated by means of theremaining motor windings.

A first aspect of the invention provides a blood pump for percutaneousinsertion such as e.g., intravascular application. The blood pumpcomprises an electrical motor for driving the blood pump. The electricalmotor comprises at least tree motor winding units. Each motor windingunit is arranged and configured to be individually connected to a powersupply through two corresponding separate phase supply lines one ofwhich is connected to one of two motor winding unit terminals and theother is connected to the other one of the motor winding terminals.

A particular motor winding unit includes at least one correspondingmotor winding, but is not limited to only one particular winding. Thatis to say, a motor winding unit may include more than one winding. Inparticular, a motor winding unit may include more than one motor windingwhich are connected in parallel to each other. For example, a motorwinding unit may include multilayer windings in which more than onewinding are implemented in different layers and are connected inparallel forming the motor winding unit. For example, one winding mayconsist of two parallel connected wirings disposed in different layersand connected in parallel forming the respective motor winding unit.

Preferably, the electrical motor is a synchronous motor. Mostpreferably, the motor is a permanent magnet excited synchronous motor,i.e., comprises a rotor including a permanent magnet.

Preferably, the electrical motor comprises at least three motor windingunits and for each motor winding unit two corresponding phase supplylines. In a particular embodiment the electrical motor comprises threemotor winding units, wherein each of the corresponding motor windingunit terminals is connected to one corresponding phase supply line.

A second aspect of the invention provides a motor controller for drivingand controlling the electrical motor of a blood pump according to thefirst aspect of the present invention. The motor controller comprisescorresponding switchable phase supply line driving units for each motorwinding unit. Each switchable phase supply line driving unit isconnected via corresponding two-phase supply lines with one of the motorwinding units.

Preferably, the phase supply line driving units are implemented by twohalf bridge units which are switchable for a cooperative control of theelectrical power supplied to each of the motor winding units.

Preferably, the motor controller comprises at least one of: respectivephase current measuring units for measuring the actual value of theelectrical current through the corresponding motor winding unit; a totalcurrent measuring unit for measuring the actual value of the totalelectrical current through all motor winding units; and respectivemeasuring units configured for measuring a respective induced backelectromagnetic force, back EMF, voltage also called counterelectromagnetic force, CEMF, voltage for each motor winding units at themoment when the respective motor winding unit is not driven, i.e. therespective motor winding unit is disconnected from the power supply.

Preferably, the motor controller comprises a control unit operativelyconnected to and for controlling the phase supply line driving units andconfigured to drive and control at least one of the rotational speed ofthe electrical motor, the rotational direction of the electrical motor,and the torque produced by the electrical motor.

Preferably, the control unit is configured to detect a fault in one ofthe motor winding units. Further, the control unit is configured, incase of a detected faulty motor winding unit, to switch off thecorresponding phase supply line driving unit of the faulty motor windingunit and to further operate the electrical motor by the remaining motorwindings. Alternatively, the control unit may be configured to furtherdrive the faulty motor winding unit with adjusted parameters and tofurther operate the electrical motor by all motor windings. That is tosay, the blood pump can be kept in operation by means of the remainingmotor winding units alone or by means of all motor winding units whereinthe faulty motor winding unit is operated with adjusted drivingparameters.

Preferably, a motor winding unit is determined being faulty in case ofat least one of:

(a) an interruption in the wire of the motor winding unit or in at leastone of the corresponding phase supply lines of the motor winding unit;

(b) a current leakage of the motor winding unit to a casing of theelectrical motor;

(c) a short circuit between wire turns of the motor winding unit.

Preferably, the control unit is configured to detect the faulty motorwinding unit, i.e., one of the afore-mentioned faults (a) to (c) basedon at least one of: the respective actual electrical current through themotor winding unit or motor winding units and a comparison of the actualelectrical voltage of the motor winding unit or motor winding units.

Alternatively, a fault in a motor winding unit may comprise a shortcircuit between the wires of two of the motor winding units, i.e.,resulting in the two motor winding units being faulty. Preferably, thecontrol unit is configured to detect the two faulty motor winding unitsbased on a comparison of the actual electrical current through the twofaulty motor winding units. Preferably, in case of such two faultywinding units, the control unit is configured to determine one of thetwo faulty motor winding units as the faulty motor winding unit thecorresponding phase supply line driving unit is to be switched off or tobe operated with adjusted parameters.

A third aspect of the invention provides a blood pump system comprisinga blood pump according to the first aspect of the present invention anda motor controller according to the second aspect of the presentinvention.

A fourth aspect of the invention provides a control method forcontrolling the power supply to motor winding units of a blood pump,preferably according to the first aspect of the present invention. Themethod comprises: (i) detecting a fault in one of the motor windingunits; (ii) in case of a detected faulty motor winding unit: in a firstalternative, switching off a corresponding phase supply line drivingunit driving the faulty motor winding unit and further operating theelectrical motor by controlling the phase supply line driving units ofthe remaining motor windings; in a second alternative, adjusting drivingparameters of the faulty motor winding unit and further operating theelectrical motor by controlling the phase supply line driving units ofall motor windings.

Preferably, the step of detecting a fault in one of the motor windingunits comprises but is not limited to detecting at least one of:

(a) an interruption in the wire of the faulty motor winding unit or inthe corresponding phase supply lines of the faulty motor winding unit;

(b) a current leakage of the faulty motor winding unit to a casing ofthe electrical motor;

(c) a short circuit between wire turns of the faulty motor winding unit;and

(d) a short circuit between the wires of two of the motor winding units.

Preferably, the step of detecting a fault in one of the motor windingunits is based on at least one of the respective actual electricalcurrent through the motor winding units, a comparison of the actualelectrical voltage drop at the motor winding units, and a comparison ofthe actual electrical current through the faulty motor winding units.

A fifth aspect of the invention concerns the use of at least threeindependent motor winding units in an electrical motor for driving of ablood pump for percutaneous insertion. Each motor winding unit isarranged and configured to be individually connected to a power supplyvia corresponding two separate phase supply lines which are connected toa respective one of two motor winding unit terminals of thecorresponding motor winding unit.

Finally, with regard to the blood pump of the first aspect of thepresent invention, the motor controller of the second aspect of thepresent invention, the blood pump system of the third aspect of thepresent invention, the control method of the fourth aspect of thepresent invention, or the use of the fifth aspect of the presentinvention, in any case, the electrical motor is preferably an integralcomponent to the blood pump. Since the blood pump is configured forbeing completely inserted percutaneously into a patient's body, theelectrical motor as integral part of the blood pump is inserted as well,when the blood pump is inserted into a patient. In turn, the motorcontroller for providing electrical power to and controlling of theelectrical motor is preferably located outside the patient's body. Justa connection for power supply to and control of the operation of theelectrical motor is to be passed through a catheter form outside apatient percutaneously into the body of the patient to the blood pumpand correspondingly to the electrical motor.

DETAILED DESCRIPTION OF THE DRAWINGS

Hereinafter the invention will be explained by way of examples withreference to the accompanying drawings; in which

FIG. 1 shows an example for a VAD for percutaneous insertion driven byan electrical motor.

FIG. 2 shows circuitry configurations for three motor winding units,namely (a) the delta configuration, (b) the star or wye configuration,and (c) configuration with open wiring ends.

FIG. 3 illustrates principle of driving an electrical motor with threemotor winding units in star configuration by pulse with modulatedcontrol of corresponding switches between a power supply and the threepower supply lines of the motor winding units.

FIG. 4 shows one particular embodiment of the herein proposed newconfiguration of the motor winding units in the electrical motor of ablood pump for percutaneous insertion, and further illustrates by meansof a simplified schematic circuitry diagram the basic configuration ofthe driving stage for the electrical motor.

DETAILED DESCRIPTION

FIG. 1 shows an example for a VAD for percutaneous insertion driven byan electrical motor comprising corresponding motor winding units. TheVAD is a micro axial rotary blood pump 50, in particular acatheter-based micro axial rotational blood pump for percutaneousinsertion through a patient's vessel into a patient's heart (in thefollowing for short called “blood pump 50”). Such a blood pump is, forexample, known from U.S. Pat. No. 5,911,685 A.

The blood pump 50 is based on a catheter 10 by means of which the bloodpump 50 can be temporarily introduced via a vessel into a ventricle of apatient's heart. The blood pump 50 comprises in addition to the catheter10 a pumping device fastened to the end of a catheter tube 20. Therotary pumping device comprises an electrical motor 51 and a pumpsection 52 located at an axial distance therefrom. A flow cannula 53 isconnected to the pump section 52 at its one end, extends from the pumpsection 52 and has an inflow cage 54 located at its other end. Theinflow cage 54 has attached thereto a soft and flexible tip 55. The pumpsection 52 comprises a pump housing with outlet openings 56. Further,the pumping device comprises a drive shaft 57 protruding from theelectrical motor 51 into the pump housing of the pump section 52. Thedrive shaft 57 drives an impeller 58 as a thrust element. Duringoperation of the blood pump 50, blood can be sucked through the inflowcage 54 and discharged through the outlet openings 56 by means of therotating impeller 58 driven by an electrical motor 50 via the driveshaft 57.

Through the catheter tube 20 of the catheter 10 pass three lines, namelytwo signal lines 28A, 28B and a power supply line 29 for supplingelectrical power to the electrical motor 51 of the pumping device. Thesignal lines 28A, 28B and the power-supply line 29 are attached at theirproximal end to a control device (not shown) for control of the pumpingdevice. The signal lines 28A, 28B are parts of blood pressure sensorswith corresponding sensor heads 30 and 60, respectively. The powersupply line 29 comprises separate phase supply lines for supplyingelectrical power to each motor winding unit of the electrical motor 51of the motor section. The electrical motor 51 is preferably asynchronous motor. In an exemplary configuration the electrical motorcomprises three motor winding units for driving a rotor (not shown)coupled with the drive shaft 57. The rotor may comprise at least onefield winding. Alternatively, the rotor comprises a permanent magnetresulting in a permanent magnet excited synchronous motor. In aparticular embodiment, a particular motor winding unit includes twoparallel connected windings which are disposed in different layers andconnected in parallel.

The blood pump 50 is a micro axial rotary blood pump, wherein “micro”indicates that the size is small enough so that the blood pump can bepercutaneously inserted into a heart's ventricle via blood vesselsleading to the ventricle. This also defines the blood pump 50 as an“intravascular” blood pump for percutaneous insertion. “Axial” indicatesthat the arrangement of the electrical motor 51 for driving the pumpsection 52 are arranged in an axial configuration. “Rotational” meansthat the pump functionality is based on the rotating operation of thetrust element, e.g., the impeller, driven be the rotational electricalmotor 51.

Preferably and as shown in FIG. 1, the electrical motor 51 is onecomponent of the blood pump 50 which is configured to be completelyinserted percutaneously into a patient's body. Usually, the blood pump50 is inserted into a patient's body via vessels, for example leading toa ventricle of the patient's heart. As discussed above, the blood pump50 is based on the catheter 10 by which the insertion of the blood pump50 through the vessels can be performed and through which the powersupply line 29 can be passed for supplying electrical power to andcontrol of the electrical motor 51. That is to say, a motor controller(e.g., 100 in FIG. 4) providing electrical power to and controlling ofthe electrical motor 51 is located outside the patient's body. Thus,only the connection (e.g., 29) for power supply to and control of theoperation of the motor 51 run through the catheter 10. This is totallydifferent to blood pumps, which are driven via a rotating driving wirelaid through a catheter so that just the pump section is to be insertedinto a patient's body whilst the driving electrical motor can be locatedoutside the patient's body. In this case, a failing electrical motor maybe replaced more easily.

FIG. 2 shows respective circuitry configurations for the electricalmotor 51 of the blood pump 50 in FIG. 1. By way of example, theelectrical motor comprises three motor winding units Lu, Lv, Lw. In FIG.2(a) the motor winding units Lu, Lv, Lw are connected in the deltacircuit configuration. In FIG. 2(b) the motor winding units Lu, Lv, Lware connected in the star or wye circuit configuration.

FIG. 2(c) shows the motor winding units Lu, Lv, Lw in a configurationwith open wiring ends, commonly called “open end windings”configuration. The shown configuration is characterized by the fact thatthere is no intended circuit interconnection between anyone of the threemotor winding units Lu, Lv, Lw to the other two motor winding units. Inthis configuration, anyone of the tree motor winding units Lu, Lv, Lwcan be supplied with electrical power independently from the other motorwinding units.

It is worth to be noted, a particular motor winding unit includes atleast one particular motor winding, but is not limited to one winding. Amotor winding unit may include more than one motor winding. Inparticular, a motor winding unit may include more than one motor windingwhich are connected in parallel to form the motor winding unit. Forexample, one motor winding unit may consist of two parallel connectedwirings. The different windings may be disposed in different layers andmay be connected in parallel at their respective wiring ends forming theterminals of the motor winding unit.

FIG. 3 illustrates the conventional driving of the electrical motor 51-1having three motor winding units Lu, Lv, Lw in the configuration of FIG.2(b) by means of a pulse with modulated control of correspondingswitches Su1 and Su2, Sv1 and Sv2, Sw1 and Sw2 respectively connected toone of two power supply nodes Us, Ug and respectively to only one ofthree power supply lines L1, L2, L3 supplying one corresponding motorwinding unit Lu, Lv, Lw.

The electrical motor 51-1 comprises the motor winding configuration asused in the micro axial rotary blood pump known from U.S. Pat. No.5,911,685 A. The three motor winding units Lu, Lv, Lw are connectedtogether with one of their terminals at a star node SN while therespective other terminal of each motor winding unit are connectedthrough one of corresponding power supply lines L1, L2, L3 tocorresponding middle nodes MN1, MN2, MN3 of respective three halfbridges H1, H2, H3 respectively comprising two semiconductor switches,e.g., power MOSFETs, illustrated as the switches Su1 and Su2, Sv1 andSv2, Sw1 and Sw2. Each of the three half bridges H1, H2, H3 defines arespective phase supply line driving unit which is controlled by controlunit 1. The three half bridges H1, H2, H3, i.e., phase supply linedriving units, may be integrated in or implemented by one driving unitDU.

Each of the half bridges H1, H2, H3 is controlled by control unit 1configured to control the respective switches Su1 and Su2, Sv1 and Sv2,Sw1 and Sw2 by means of pulse width modulation such that the waveform ofthe voltages driving the particular motor winding units Lu, Lv, Lw havea 120.degree. phase difference with respect to anyone of the waveformsof the respective voltages driving the other two motor windings.

The half bridges H1, H2, H3 are respectively connected to the controlunit 1 which also provides the supply voltage Us and a reference voltageUg, e.g., ground. The respective control of the switches in one halfbridge H1, H2, H3 is indicated in FIG. 3 by corresponding arrows fromthe control unit 1 to the respective switches Su1 and Su2, Sv1 and Sv2,Sw1 and Sw2. By switching the respective half bridges H1, H2, H3, therespective electrical current supplied to the corresponding motorwinding unit Lu, Lv, Lw is switched resulting in a corresponding changeof the magnetic field produced by the particular motor winding unit.Thereby, the motor winding units produce a rotating magnetic field formoving a rotor (not shown) of the motor 51-1. The rotor comprising anexcited field winding is correspondingly forced to rotate.

The corresponding control of the switches Su1 and Su2, Sv1 and Sv2, Sw1and Sw2 in the half bridges H1, H2, H3 (phase supply line driving units)allows for control of the rotational direction and rotational velocityof the electrical motor 51-1 as well as for the torque produced by theelectrical motor 51-1. For example, in the known blood pump 50 shown inFIG. 1 the synchronous motor 51 with three motor winding units Lu, Lv,Lw is operated in star configuration. Accordingly, the supply line 29shown in FIG. 1 running through the catheter tube 20 comprises threephase supply lines L1, L2, and L3 for supplying electrical power to therespective motor winding unit.

FIG. 4 shows one particular embodiment of the herein proposed newconfiguration of the motor winding units in the electrical motor 51-2 ofa blood pump for percutaneous insertion such as the one shown in FIG. 1.Further, FIG. 4 illustrates by means of a simplified schematic circuitrydiagram the basic configuration of a driving stage for the electricalmotor 51-2.

As mentioned before and as illustrated by FIG. 1, the electrical motor51-2 is one integral component of the blood pump 50. Thus, with theblood pump 50, also the electrical motor 51-2 is completely insertedpercutaneously into a patient's body. Also as discussed above, the bloodpump 50 is based on the catheter 10 by which the insertion of the bloodpump 50 through the vessels is performed and through which the powersupply line 29 is guided for supplying electrical power to and controlof the electrical motor 51-2. The power supply line 29 includes sixindividual separate phase supply lines Lw1, Lv1, and Lu1, Lw2, Lv2, andLu2 (to be discussed in more detail below). A motor controller 100amongst others providing electrical power to and controlling theelectrical motor 51-2 will be located outside the patient's body. Inother words, the connection for power supply to and control of theoperation of the motor 51-2 pass through the catheter 10.

The electrical motor 51-2 comprises the three motor winding units Lu,Lv, Lw. It is noted that there may be used more than three motor windingunits as well. Each motor winding unit Lu, Lv, Lw is individuallyconnected at both respective motor winding unit terminals LwE1 and LwE2,LvE1 and LvE2, and LuE1 and LuE2 with one individual separate phasesupply line Lw1, Lv1, and Lu1, Lw2, Lv2, and Lu2. Each of the two-phasesupply lines of one particular motor winding unit Lu, Lv, Lw isconnected to one corresponding half bridge circuit DH1, DH2, DH3, DL1,DL2, DL3. Each half bridge circuit DH1, DH2, DH3, DL1, DL2, DL3 iscomprised of two corresponding semiconductor switches SwH1 and SwH2,SvH1 and SvH2, SuH1 and SuH2, SwL1 and SwL2, SvL1 and SvL2, SuL1 andSuL2, as described in connection with FIG. 3.

For instance, with respect to the motor winding unit Lw, a first windingunit terminal LwE1 is connected via a first phase supply line Lw1 to amiddle node MNH1 of the half bridge circuit DH1, while the secondwinding end LwE2 is connected via a second phase supply line Lw2 to themiddle node MNL1 of the corresponding second half bridge circuit DL1.Each of the two half bridge circuits DH1, DL1 comprises two respectivesemiconductor switches SwH1 and SwH2, SwL1 and SwL2. The two half bridgecircuits DH1, DL1 together define the phase supply line driving unit forthe motor winding unit Lw. The same applies correspondingly for theother half bridges and motor winding units.

In comparison to the configuration shown in FIG. 3, the electrical motor51-2 in FIG. 4 is driven and controlled by a motor controller 100comprising in principle two driving units DU1, DU2. Each of the twodriving units DU1, DU2 is respectively connected to respective firstwinding unit terminals of the motor winding units Lu, Lv, Lw. In aparticular implementation, for example, the driving units DU1, DU2 maybe implemented by an integrated circuit (IC), such as a DRV8312 threephase pulse width modulation driving unit from Texas Instruments.

For measuring the actual electrical current Iv, Iu, Iw passing throughone particular motor winding unit Lw, Lv, Lu, the driving units DU1, DU2are connected to respective current measuring units IM1, IM2, IM3 whichin principle are connected in series with the corresponding motorwinding unit Lw, Lv, Lu. For example, the actual electrical currentpassing through one particular motor winding unit Lw, Lv, Lu can bedetermined as corresponding to the electrical voltage drop over acurrent sensing element, such as a shunt resistor. In the embodimentshown in FIG. 4, the current sensing units IM1, IM2, IM3 are implementedby corresponding shunt resistors Rw, Rv, Ru.

In a corresponding manner, the motor controller 100 comprises ameasuring unit ITM for the total electrical current passing through allmotor winding units Lw, Lv, Lu. The total current measuring unit ITMcomprises a current sensing element and is connected in series with acommon node of all phase supply lines, which in principle are connectedas the motor winding units itself in parallel to each other. The currentsensing unit ITM for the total electrical current is implemented by ashunt resistor Rtotal, the voltage drop thereof can be measured and isproportional to the total electrical current Itotal.

Further, the control unit 120 comprises sensing inputs for receiving themeasurement values for the actual electrical currents Iv, Iu, Iw foreach individual motor winding unit Lw, Lv, Lu as well as for the totalelectrical current Itotal passing through all motor winding units Lw,Lv, Lu. Further the control unit 120 is operatively connected to thepower supply unit 110 for receiving the actual voltage supplied via thedriving units DU1, DU2.

Furthermore, a corresponding voltage measurement is also implemented atthe respective middle nodes MNH1, MNH2, and MNH3 in driving unit DU1and/or MNL1, MNK2, MNL3 in driving unit DU2 for measuring the inducedcounter electromagnetic force, CEMF, voltages at each motor winding unitwhen the respective motor winding unit is currently not driven, i.e.,any one of the switches in the corresponding half bridges is open.

Further, output control lines run from the control unit 120 to therespective semiconductor switches of the half bridges DH1, DH2, DH3,DL1, DL2, DL3 for control thereof.

It is noted the current sensing lines and the control lines are onlyshown schematically in FIG. 4 to keep the Figure simple; by way ofexample, there is an arrow from the current measuring unit IM1 withshunt resistor Rw to the control unit 120 representing the input of ameasuring value for the actual electrical current lw in the motorwinding Lw to the control unit 120. Similarly, an arrow from the controlunit 120 to the semiconductor switch SwL2 of the half bridge DL1 in thedriving unit DU2 illustrates that the operation of the switch SwL2 isunder control of the control unit 120 as are the other switches.

In principle the control of the rotational direction, rotational speedand the produced motor torque of the electrical motor 51-2 is similar tothat in the configuration shown in FIG. 3. However, the herein proposedconfiguration provides some particular advantages.

Firstly, the control unit 120 is configured to detect faults in anyoneof the motor winding units Lu, Lv, Lw. Based on a detected faulty motorwinding unit, the control unit 120 is configured to switch off thecorresponding half bridges DH1, DH2, DH3, DL1, DL2, DL3 connected to thefaulty motor winding unit, once the particular motor winding unit wasdetected as faulty. Due to the individual control of each of the motorwinding units Lu, Lv, Lw, the electrical motor 51-2 can be furthercontrolled and operated, alternatively by means of the remaining motorwinding units only, particularly by control of the correspondingremaining half bridges, or by means of all motor winding units, whereinthe driving parameters for the faulty motor winding unit are adjusted.

Advantageously, a faulty motor winding unit may be defined at least bydetecting one of the following circuitry faults.

For example, there may be an interruption in the wire of the motorwinding unit or in the corresponding phase supply lines of a motorwinding unit, which corresponds to a fault in the particular motorwinding unit.

For example, due to an insulation failure in one of the motor windingunits there may be a current leakage between the motor winding and thecasing of the electrical motor 51-2.

For example, there may be a short circuit between wire turns of aparticular motor winding unit resulting in a reduced inductance of thecorresponding motor winding unit, also defining a faulty motor windingunit.

In all these forgoing fault cases, the control unit 120 is configured todetect the respective faulty motor winding unit based on therespectively measured actual electrical current through the motorwinding units and/or a comparison of the actual electrical voltage dropat the motor winding units.

Moreover, for example, a fault in a motor winding unit may be defined bya short circuit between the wires of two motor winding units. Thecontrol unit 120 is also configured to detect such two faulty motorwinding units e.g., based on a comparison of the actual electricalcurrent through the motor winding units. In such a fault case, thecontrol unit 120 is configured to determine one of the two faulty motorwinding units as the faulty motor winding unit for which thecorresponding half bridges DH1 and DL1, DH2 and DL2, or DH3 and DL3 areto be switched off and/or which corresponding half bridges are to beoperated with adjusted parameters. Consequently, as discussed above, theelectrical motor 51-2 can be further operated by means of the remainingmotor units.

In the case of the blood pump for subcutaneous insertion into a heart'sventricle the herein described error tolerant configuration andoperation of the motor winding units of the electrical motor driving theblood pump reduces the risk on patients by a total drop out of the bloodpump. Further to this the risk imposed by removing the blood pump fromthe patient for replacing it by a new one be reduced as well.

Finally, the present disclosure proposes a new blood pump forpercutaneous insertion and/or intravascular application comprising anelectrical motor for driving the blood pump, the electrical motorcomprising at least three motor winding units, wherein each motorwinding unit is individually connectable to a power supply via twoseparate phase supply lines connected to the respective motor windingunit terminals.

Further, the present disclosure proposes a motor controller for drivingand controlling the electrical motor of the blood pump, wherein themotor controller comprises corresponding phase supply line driving unitsfor each motor winding unit of the electrical motor of the blood pumpwhich phase supply line driving units are connected via thecorresponding two-phase supply lines with the corresponding motorwinding unit.

Furthermore, the present disclosure proposes a corresponding blood pumpsystem comprising the blood pump and the motor controller.

Moreover, the present disclosure proposes a corresponding control methodfor controlling the power supply to the motor winding units of the bloodpump, wherein the method comprises: detecting a fault of one of themotor winding units, and in case of a detected faulty motor windingunit, switching off the corresponding phase supply line driving units ofthe faulty motor winding unit and further operating the electrical motorby controlling the phase supply line driving units of the remainingmotor windings, or alternatively further operating all motor windingunits wherein the driving parameters for the faulty motor winding unitare adjusted driving parameters.

Finally, the present disclosure proposes the use of at least threeindependent motor windings in an electrical motor for driving of a bloodpump for percutaneous insertion and/or intravascular application theblood pump, which motor windings are individually connected tocorresponding power supply via corresponding two separate phase supplylines connected to respective motor winding ends of one of the at leastthree motor windings.

1. A blood pump system for percutaneous insertion comprising: a bloodpump comprising: a pump housing with outlet openings; a drive shaft thatdrives an impeller as a thrust element; a catheter comprising a cathetertube through which passes a power supply line; an electrical motor fordriving the blood pump, the electrical motor comprising at least threemotor winding units, wherein each motor winding unit is arranged andconfigured to be individually connected to the power supply via thepower supply line comprising separate phase supply lines connected torespective motor winding unit terminals; a motor controller for drivingand controlling an electrical motor of the blood pump, the motorcontroller comprising corresponding phase supply line driving units foreach motor winding unit which are respectively connected through thecorresponding phase supply lines with one of the motor winding units;and a control unit configured to control the phase supply line drivingunits to operate the electrical motor, wherein the control unit isconfigured to detect a fault in one of the motor winding units whereinthe control unit is further configured, in case of a detected faultymotor winding unit, to adjust driving parameters for the faulty motorwinding unit and to further operate the electrical motor by all motorwinding units.
 2. The blood pump system of claim 1, wherein the motorcontroller further comprises at least one of: respective phase currentmeasuring units for measuring an actual value of an electrical currentthrough a corresponding motor winding unit; a total current measuringunit for measuring an actual value of a total electrical current throughall motor winding units; and respective measuring units configured formeasuring a respective induced counter electromagnetic force, CEMF, formotor winding units not driven.
 3. The blood pump system of claim 1,wherein each of the phase supply line driving units is implemented bytwo corresponding half bridge units configured to be switchable for acooperative control of electrical power supplied to a correspondingmotor winding unit.
 4. The blood pump system of claim 1, wherein thecontrol unit is configured to control the phase supply line drivingunits to operate the electrical motor, to drive and control at least oneof a rotational speed of the electrical motor, a rotational direction ofthe electrical motor, and a torque produced by the electrical motor. 5.The blood pump system of claim 1, wherein the faulty motor winding unitis defined by at least one of an interruption in a wire of the motorwinding unit or in the corresponding phase supply lines of the motorwinding unit; a current leakage of the motor winding unit to a casing ofthe electrical motor; and a short circuit between wire turns of themotor winding unit; and wherein the control unit is further configuredto detect the faulty motor winding unit based on at least one of therespective actual electrical current through the motor winding units ora comparison of the actual electrical voltage of the motor windingunits.
 6. The blood pump system of claim 1, wherein the electrical motoris an integral component of the blood pump, which is configured forbeing completely inserted percutaneously into a patient's body so thatwhen the blood pump is inserted, the motor controller for providingelectrical power to and controlling the electrical motor is locatedoutside the patient's body.
 7. A blood pump system for percutaneousinsertion comprising: a pump housing with outlet openings; a drive shaftthat drives an impeller as a thrust element; a catheter comprising acatheter tube through which passes a power supply line; an electricalmotor for driving rotation of the impeller of the blood pump, theelectrical motor comprising: at least three motor winding units, whereineach motor winding unit is arranged and configured to be individuallyconnected to a power supply via the power supply line comprisingseparate phase supply lines connected to respective motor winding unitterminals; a motor controller for driving and controlling an electricalmotor of the blood pump system, the motor controller comprisingcorresponding phase supply line driving units for each motor windingunit which are respectively connected through the corresponding phasesupply lines with one of the motor winding units; and a control unitconfigured to control the phase supply line driving units to operate theelectrical motor, wherein the control unit is configured to detect afault in one of the motor winding units wherein the control unit isfurther configured, in case of a detected faulty motor winding unit, toadjust driving parameters for the faulty motor winding unit and tofurther operate the electrical motor by all motor winding units.
 8. Theblood pump system of claim 7, wherein the electrical motor is apermanent magnet excited synchronous motor.
 9. The blood pump system ofclaim 7, wherein the electrical motor is an integral component of theblood pump, which is configured for being completely insertedpercutaneously into a patient's body so that when the blood pump isinserted, the motor controller for providing electrical power to andcontrolling the electrical motor is located outside the patient's body.10. The blood pump system of claim 7, wherein the electrical motorcomprises three motor winding units, each motor winding unit beingconnected to corresponding phase supply lines.